the biggest problem with ATI drivers has been the crossfire scaling performance, as well as a few issues with multiscreen setups. The issues with x-fire performance has been fixed with the 6900 series cards, with the scaling in many instances even better than nvidias. So that's not an issue anymore. That being said, I myself had no issues with drivers or performance on my 5870s in xfire the year i had them, and my flashed 6950s work perfectly fine as well..if you take the time to do some research you'll find this to be the general consensus.